I ran across a post a while back on this, but for the life of me, I can't find it again to see if it was updated. My 01 CL-S randomly makes a humming noise for about 2 or 3 seconds while the car is off, in the garage. It will reoccur every few minutes. I cannot localize the sound, but it may be coming from the trunk area. It almost sounds like a cell phone vibrating, or the power seat motor, but of course there is no phone in the car and the seat is not moving by itself. I'm beginning to think the car is possessed though. It seems to do it more when the engine is still warm after driving. I don't seem to hear it in the mornings after the car has sat all night.

It may be no big deal, as it doesn't seem to affect anything at all. But as you can imagine, it is annoying to not know why. Thanks for any input.

 

Take the fuel pump fuse out( drivers side kick panel, I believe second from the bottom ,15A) will see what happens. Fuel pump does 2-3 second fuel pressure buildup right when you turn key to pos 2, it sounds like vibrating phone and its in the trunk.

 

Is that humming a problem? My car does it too. Freaked me the hell out the first time I heard it.

It sounds just like the fuel pump priming, but it happens when the car has been off for awhile and I just unlock the doors or pop the trunk.

 

I made a post about that a while ago, no one responded. My car does it too. wtf it ran good untill the tranny shit on me.

 

I have an 03 and my car does it too. It seems to occur in regular intervals of about 2 minutes. I just hope that it won't drain my battery one day and I end up stuck somewhere.

 

It still sounds like fuel pump buzzing , the only thing that might have trigger that with everything off is PGM-FI relay, known as a pretty crappy part on honda products

 

i posted about this a while ago also but in the accord forums. Now i have a CL and it's doing the same thing. The sound is coming from a black box under the car by the rear passenger seat on the driver side. It's call an EVAP canister. It's used for emissions, it's supposed to bring unused fuel back to the gas tank.

I think it's number 5 in the illustration

 

Exactly! fuel pump is inches away from the evap tank which is an empty tank with 2 valve solenoids, used for balancing tank pressure and vapor condensing.

 

so does the noise mean that its going bad?

 

No , its definately not the pumps fault.

 

no it's not going bad and it is definately not the pump. The humming is coming directly from that EVAP canister. i have gone under and checked.

 

So the EVAP canister. It feels so good to finally place a name with that strange little noise! If it means I'm saving a tad bit of gas....sounds good to me. And if I did have to localize the sound, that would be my best guess where it's coming from. The passenger rear area. Thanks for all of your help.